1. Field of the Invention
The present invention relates to computer devices, such as disk drives. More particularly, the present invention relates to a computer device employing a sliding window to set an idle mode timeout interval.
2. Description of the Prior Art
Mobile computer devices, such as laptop computers, typically incorporate a disk drive comprising a head disk assembly (HDA) and control circuitry. Since minimizing power consumption is of particular concern in mobile devices, a power management algorithm is typically implemented wherein the disk drive enters an idle mode if a host command is not received within a predetermined timeout interval. It is important to set the timeout interval to an appropriate value since there is a certain amount of recovery time and energy dissipated to exit the idle mode when a command is received. That is, if the timeout interval is too short, the disk drive may consume more power and lose performance due to the latency in repeatedly entering/exiting the idle mode as opposed to remaining in an active mode.
Prior art disk drives have employed a fixed timeout interval for entering the idle mode; however, a fixed timeout interval may not result in optimal performance depending on the operating environment of the disk drive. For example, if the disk drive is receiving intermittent host commands over long command intervals, a more optimal power/performance level may be achieved by reducing the timeout interval so that the disk drive enters the idle mode soon after processing each host command.
There is, therefore, a need to optimize an idle mode timeout interval in a computer device, such as a disk drive, to account for variations in the operating environment.